Sorry not in your area so can't make a recommendation, other than to say a lot of the routine stuff is very easy to do yourself, at least you know it's been done, learn about your ride and save money.
Oil change is easy and can be done with just the l.h side panel (30 second job) removed, the transmission oil and gear oil are all along that side and an hour would do all three. The CVT filter is the other side and just a little fiddly to get at some of the screws but also an easy DIY, this is one that may have been missed.
Spark plugs are a bit of a bugger as they're behind the radiator, which swings to one side but it's still pretty cramped and easier with the front mudguard removed, use Iridiums and basically "fit and forget". Probably the most important is checking brake pads and cleaning the pistons to avoid them seizing, a pencil fits neatly into the drilled disc holes, you'd be amazed how much crud accumulates and 5 minutes poking holes can be rewarding!!
You should check the stopper bolt, because of a few reported issues and it's also easy (no panel removal) and about a fiver to replace.
You can see a DIY Video guide to all this and more here:
Le Dude Videos
You may find some kind soul has uploaded the service manual here:
AN650 even if you don't attempt any DIY these are very useful to have.
You will likely pay out hundreds for a dealer to do this, a non-Suzuki place will save some provided they're familiar with the B650.
Here's an overview:
Oil (Engine & Transmission)[tab=30]due every 4,000/6mnths & 7,500mls/12mnths
Gear Oil (SAE80/90 GL5)[tab=30]due every 7,500mls/12mnths
Air Cleaner[tab=110]due every 11,250mls or 18mth
Oil Filter[tab=120]due every 11,250mls or 18mth (some swap on every oil change - HiFlo HF138)
CVT filter[tab=120]due every 11,250mls or 18mth
Coolant & Brake Fluid[tab=50]due every 2 years
